The first is obviously about the beneficiary, the second (not so obvious), is about claimants to title/ownership, both the rightful (but absent) claimant and those who contend for it in his absence. Contrary to popular belief (guilty!) there is no mention of life.

Never bothered meself, but you might be interested in researching why Henry 8th hated and tried to destroy the cestui que wotsit. And why after the 1707 Union with Scotland the Cestui Que Scotland Act was the first Act introduced in the brand spanking new and ever so shiny united kingdom.